Hawai‘i federal district Judge David A. Ezra today found that the Navy is violating federal law and enjoined it from carrying out its Undersea Warfare Exercises in Hawai’i’s waters without adhering to additional mitigation measures to protect marine mammals. The Navy is also required to take a hard look at the impacts of its high-intensity, mid-frequency active (MFA) sonar by preparing an Environmental Impact Statement.

Earthjustice, on behalf of Ocean Mammal Institute, Animal Welfare Institute, KAHEA: The Hawaiian-Environmental Alliance, the Center for Biological Diversity, and Surfrider Foundation’s Kaua’i Chapter, sued the Navy last May. Judge Ezra issued a preliminary injunction after finding the Navy was violating the National Environmental Policy Act (NEPA) and the Coastal Zone Management Act (CZMA), and was likely to cause harm if allowed to proceed without greater protections.

He noted the Navy’s harm threshold—173 decibels (dB)—contradicts the best available science, and “cast into serious doubt the Navy’s assertion that, despite over 60,000 potential exposures to MFA sonar, marine mammals will not be jeopardized.” The Court said further the Navy had failed to analyze reasonable alternatives to conducting its exercises in the manner it proposed, failed to notify and involve the public as required by law, and failed to take into account the potential for serious harm from an exceptionally controversial activity.

Learn more about the lawsuit and the impacts of high-intensity mid-frequency (MFA) sonar on Hawaii’s marine mammals.